Canning Jar Safety

June 12, 2009(updated on October 3, 2018)


On Monday, I wrote a post about canning in vintage jars. Tara left a comment, asking about the safety of these jars. I briefly responded to her question there, but it’s an important enough question that I wanted to make sure that the query and my answer to it got its moment in the sun.

So here it goes. These jars are not recommended by the USDA. The only home canning method endorsed by the USDA is the one that involves Ball/Kerr/Mason jars and the two-part lids. Thing is, Weck jars aren’t endorsed either and they are widely sold today and are an extremely popular style of canning jar in Europe. These vintage bailing wire jars are the functional equivalent of the Weck jars. That fact leads me to extrapolate that if you treat the vintage jars with the same safety precautions that are recommended for the Weck jars (those safety precautions come from the Weck company, not from the USDA) and check the seal after canning by lifting the jar by the lid, your canned item will be just fine. As an added precaution, I only plan on using these vintage jars to can high sugar items like jams and jellies.

The thing to remember is that the government safety precautions are written for the absolute canning novice. They want to make the canning process as safe and idiot-proof as possible. And they’re right to do so, because people have gotten sick from eating poorly canned/preserved foods. While I wouldn’t recommend that you can in vintage jars during your very first canning session, I do think that it’s a viable option as you explore and want to try other styles of jars.

However, just because I’ve offered instructions on how to do this style of canning, I do not intend to endorse other antiquated styles of food preservation. I’m not going to start sealing jars with paraffin wax (despite my father’s happy memories of licking his grandmother’s jam off of wax discs). But I will continue to can in these bailing wire glass jars, using fresh rubber seals and following safe canning procedures (making sure my jars are clean and undamaged, doing the hot water process and then testing the strength/quality of the seal once the jars are cool by lifting the jar by the lid). I like the way they look, I like how sturdy they are and I like that the only waste produced is the rubber seal. All that said, don’t do it if it makes you uncomfortable.

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22 thoughts on "Canning Jar Safety"

  • I’ve used these jars alot, tho not in the stuff I sell. Here’s what my experience is: I stick to non potentially hazardous foods like jam or jelly, that even if there is a failure won’t actually kill you. Where I have had problems is that the lids sometime shatter after heavy use and you might find a mess in the HW bath

  • No wax!?! 🙂 Thanks for addressing this. It does make sense that these would be “safer” for canned items with high sugar content-as you are more likely to get mold than some deadly food disease from it not being sealed properly. I have always wanted to used them for the nostalgic factor and now I do feel a little more comfortable having thought about it this way. Thanks!

  • Slightly off-topic, but do you know of any stores within Center City that sell canning supplies? I’ve just moved to the area and am eager to get a jump on jam-making before strawberry season is over. Thanks so much — I’ve really been enjoying reading your blog!

  • Tamidon, thanks for the warning about the shattered lids.

    Tara, I’m glad my response was helpful!

    Kate, check out Center City hardware stores. I used to buy jars at the hardware store at 19th and Chestnut, but they went out of business a few weeks ago. Other hardware stores might have them though. Also, I know that Foster’s will be carrying jars sometime soon (they haven’t gotten them in stock yet, but should have them this week or next).

    Additionally, if you’re up for heading a bit out of Center City, I know that the ShopRite in S. Philly (the one right by Target) carries canning supplies.

  • i canned peaches and didn’t pack enough fruit in the qt jars and then didn’t have the lid screwed on tight,they have all sealed but of course i don’t have liquid that covers all the fruit. can i reprocess them with more juice and fruit (from the other processed jars) ty

  • Cynthia, you can definitely reprocess the fruit, although the final texture of the peaches may be slightly softer than a typical canned peach. To do so, empty all your fruit and juice into a saucepan and bring it up to a simmer. Thoroughly clean your jars and simmer a fresh batch of lids (you can’t use the same ones). Fill the jars, wipe the rims, apply lids and bands (tightening the lids well) and reprocess.

  • What do you mean exactly by “lifting the jar by the lid” for the purpose of checking for a proper seal? I am sure when you reply it will be obvious to me but I just can’t seem to wrap my brain around it right now……better to be certain anyway. Thanks.

  • Please be advised that WECK jars are nothing like the bail type jars. Bail type jars are not recommended for canning as there is no way to tell if you have a proper seal, they are 1 piece jar. As for WECK jars they are as fool proof as Ball or Kerr using 4 pieces. There is 2 ways to check for a proper seal. First once the jar has been processed the tongue on the rubber ring will point down if a proper seal has been achieved, second after the jar has completely cooled you must remove the 2 stainless steel clamps and you can lift the jar by the lid. Thank you

    1. Ok Judy, I think there is some confusion. The MODERN bail type jars, are a one peice contraption where the rubber ring is firmly stretched around the “inner neck” of the LID, and when you unlock the bail the whole lid AND ring lift off of jar. BUT what she was describing are the VINTAGE wire bail type jars where the wire clamps down OVER the top of the glass lid, instead of acting as a hinge and locking mechanism. With the VINTAGE ones the biggest issue is the age of the glass and the number of times they have been processed and finding them in sufficiently sturdy chipless state.

  • I recently canned some jam and when I was checking for proper seal, I found that when I pressed down on the center of the lids, some popped down. It has been about 18hrs since I canned the jars. I’m just wondering if I’m ok, and they are sealed. I have taken the ring off and held onto to jar by only the lid….and the lid stays on. I have done the tapping with a spoon test….and well thats just confusing. Someone please help me. I’ve canned alot of these jams already….and now I’m getting discouraged 🙁

    1. I know this post is old, but just in case anyone new comes along and reads it….no, those jars are not ok. If the center pops up and down it has not properly sealed and must be put in the fridge and used.

  • I just found out the metal canning lids are coated and have BPA in them!!!!
    My main reason for home canning is to get away from these chemicals…

    I will be using these wire bale jars for most of my pickles and jams to avoid BPA….

  • is it possible to make steamed pudding in weck canning jars and would you suggest a specific recipe

  • Just an FYI about BPA-I recently bought metal canning lids and they are now stating on the box that they are BPA free. Regarding Weck safety-I have used Weck canning jars for years. I have had one failure in the the last 10 years and it was easy to spot. The glass lid came off after I released the clamps. I always check them a day after canning and remove the clamps. People in Germany have been using these safely for a long time. I understand that the USDA is concerned about novices however it’s so easy to process with these and they are so beautiful to look at. I love to give canned goods in these jars. BTW I have your first two books and they are excellent. I have lots of preserving books but I always check these two books for a recipe first when I have an a fruit or vegetable to put up.

  • Hi, I know this is an old post, but what would be your threshold for determining what food is high-sugar/acid enough to try canning in a vintage jar? Would grape juice (made in a steamer) work? I feel like if it did spoil, it would go the route of vinegar/nasty wine, but is there a rough pH threshold you aim for?

    1. The pH cut-off to determine whether something is high or low in acid is 4.6. As long as it is below that number, I’d feel comfortable using vintage jars.

  • Marisa,
    I am a 78 year young vintage canner. I started canning with my grandmother when I was still small enough to need a step stool to help her. She had mostly wire bailing jars. When I married, my first jars were also wire bailing. I still have them and have used them for high acid canning all my life. Of course you never use them in a pressure canner, but pickles, tomatoes and other pickled or high acid items are safe in hot water bath. You must always check for chips in both the jars and glass lids.
    I even have some blue and green glass jars that I save for dry storage. I don’t want to loose them to breakage as there is no replacing them.

  • I have a dozen of these old jars. I am using them for dry storage only and not canning. My question if anyone can answer is what to you use to keep the wire from corroding? Some of the jars I picked up at the ReStore and the wires are slightly corroded and difficult to move. Thank you!!